It is known to have reverse cycle air conditioners, but they require the use of compressors and complex heat exchanger arrangements which are not necessary in the much less expensive evaporative coolers. However, the absence of compressors makes the heating of an occupied space more difficult to achieve, other than with a direct heating means such as an element or a ceramic heater.
One of the problems which is encountered however, is that for cooling purposes it is desirable that an air conditioner should discharge large volumes of air, particularly when the cooling effect is achieved by evaporation of water. Without large volumes of air humidity rises too much, and some of the effectiveness of heat transfer to the human body is lost because of reduced velocity. Reference can be made to our co-pending Application Ser. No. 08/335,737, entitled Heater Attachment for Evaporative Cooler.
The specification thereof describes means to combat the above difficulty by reducing the size of the outlet opening from the motor and fan assembly of an evaporative cooler, the reduced size being applicable only when the conditioner is in a heating mode. This is described in said Application Ser. No. 08/335,737. One method of reducing the effective size is to cause vanes of a shutter to move from an open position where they are spaced apart to a closed position where they either abut or overlap. Another method is to hinge or slide a blanketing membrane across the inner surface of the vanes if they are of the fixed type. In each case, however, it is necessary to effect the movement manually, and it is also most desirable (although not always essential in the case of ceramic heaters) to have the switching arrangement interlocked with the blanketing arrangement so that the heater can only be switched on when the vanes inhibit the usual full flow of air from the device, and at all times when the usual full flow of air is discharged from the device, the heater is switched off.
Heretofore attempts which have been made have not been as simple and inexpensive as desired, and an object of this invention is to provide a very simple arrangement wherein the control means for controlling of the outlet of a cooler also actuates a switch which is normally biased to its OFF position.
Various types of automatic switching are already known, for example the pendulum type tilt switch. However, if a micro switch is used, it may be damaged, when used in an evaporative cooler by its ancillary switch control means. For example, if the cooler is accidentally dropped on its back, it is likely that a micro switch will be damaged by the impact of its control means.
This invention also seeks to provide safety means associated with a heater switch which is operated by closure of shutter means on an evaporative cooler.
Thus in this invention there is provided an operator which is movable with respect to the structure of an evaporative cooler, and that operator is provided with a cam surface which controls a switch which is normally biased to its OFF position, but closes the switch only at the end of travel when the operator is in the position where it will effect closure of at least part of the air outlet of a heating and cooling device. The remaining part of the air outlet is in the path flow of air which also must pass over a direct heat heating type of element which can for example be a spiral nychrome wire or a ceramic type element.
As said above, it is also desirable that the switching arrangement should incorporate safety features so that, for example, if a heater/cooler combination is dropped onto its back, the switch is unlikely to be damaged, and in the invention use is made of a switch retained in its OFF position by a spring device. While the control engagement by the cam surface may be direct, the spring device may alternatively contact the micro switch through a freely movable member which is guided for its movement by guide means on the inner panel of the cooler, and is constrained in its movement sufficiently to avoid excessive deflection of the switch actuating finger.